Suppress leak in HistoryURLProviderTest with frequency scoring.

tools/valgrind/memcheck/suppressions.txt

Index: tools/valgrind/memcheck/suppressions.txt
diff --git a/tools/valgrind/memcheck/suppressions.txt b/tools/valgrind/memcheck/suppressions.txt
index 1c9ce4c587cd9870fb375da925fd574eeeb3fe27..c70cf1c1dfad70b29f0a26e31814950eb41798d3 100644
--- a/tools/valgrind/memcheck/suppressions.txt
+++ b/tools/valgrind/memcheck/suppressions.txt
@@ -7228,3 +7228,18 @@ fun:_ZN7content21RenderViewHostManager8NavigateERKNS_19NavigationEntryImplE
    fun:_ZN11jingle_glue23XmppClientSocketFactory27CreateTransportClientSocketERKN3net12HostPortPairE
    fun:_ZN11jingle_glue17ChromeAsyncSocket7ConnectERKN9talk_base13SocketAddressE
 }
+{
+   bug_250666
+   Memcheck:Leak
+   fun:_Znw*
+   fun:_ZN4base8internal20PostTaskAndReplyImpl16PostTaskAndReplyERKN15tracked_objects8LocationERKNS_8CallbackIFvvEEESA_
+   fun:_ZN4base10TaskRunner16PostTaskAndReplyERKN15tracked_objects8LocationERKNS_8CallbackIFvvEEES9_
+   fun:_ZN4base26PostTaskAndReplyWithResultI13scoped_refptrIN7history19URLIndexPrivateDataEES4_EEbPNS_10TaskRunnerERKN15tracked_objects8LocationERKNS_8CallbackIFT_vEEERKNSB_IFvT0_EEE
+   fun:_ZN7content13BrowserThread26PostTaskAndReplyWithResultI13scoped_refptrIN7history19URLIndexPrivateDataEES5_EEbNS0_2IDERKN15tracked_objects8LocationERKN4base8CallbackIFT_vEEERKNSC_IFvT0_EEE
+   fun:_ZN7history16InMemoryURLIndex28PostRestoreFromCacheFileTaskEv
+   fun:_ZN7history16InMemoryURLIndex4InitEv
+   fun:_ZN14HistoryService4InitERKN4base8FilePathEP15BookmarkServiceb
+   fun:_ZN14TestingProfile20CreateHistoryServiceEbb
+   fun:_ZN22HistoryURLProviderTest9SetUpImplEb
+   fun:_ZN22HistoryURLProviderTest5SetUpEv
+}